Back for an arm chair



FIG. 1 is a perspective view showing the new design;

FIG. 2 is a front view thereof it being understood that the rear is a mirror image of that shown.

FIG. 3 is a top view thereof; and,

FIG. 4 is a side view thereof, the opposite side view being a mirror image thereof.

The broken line showing of the environmental structure of FIG. 1 of the drawing for illustrative purposes only and forms no part of the claimed design. 

the ornamental design for back for an arm chair, as shown and described. 